Please pay particular attention to the load-on-startup element. It is used
to control the order in which servlets are started by the servlet engine.
It must have a value which is less than any other servlets making use of
the ServiceManager. This is to ensure that the ServiceManager is
initialized before any other servlets attempt to start using it.

All of the configuration files are located in the WEB-INF directory by
default. The instrument configuration file is optional. Please see the
ExcaliburComponentManagerCreator
class for details on what goes into these configuration files. Note that
the lifecycle of the ExcaliburComponentManagerCreator is managed automatically
by this servlet, so there is no need to access the class directly.

Once the servlet has been configured, other servlets may gain access to
the ServiceManager (ComponentManager), InstrumentManager and LoggerManager
via the ServletContext using the following code within a servlet:

The ExcaliburComponentManagerServlet makes use of a proxy system to manage
reference to the above managers, so it is not necessary to release them
when a servlet is done using them.

It may be necessary to add the following code to the end of the dispose method of any
servlets referencing any of the above proxies. This is because on some containers,
like Tomcat, the classloader is immediately invalidated after the last servlet is
disposed. If this happens before the managers have all been disposed, then you may
see errors in the console like: WebappClassLoader: Lifecycle error : CL stopped